Thyroid peroxidase (TPO) could serve as a prognostic indicator for predicting lymph node metastasis and recurrence in patients with papillary thyroid carcinoma, the most common form of thyroid cancer, according to a recently published study in Scientific Reports.

Thyroid cancer can be pathologically classified into papillary thyroid carcinoma (PTC), medullary thyroid carcinoma (MTC), undifferentiated thyroid carcinoma, and follicular thyroid carcinoma. However, PTC is the most common form accounting for over 80% of thyroid cancer cases.

Read more about MTC prognosis

Continue Reading

Although the prognosis is favorable in the majority of cases, lymph node metastasis is not uncommon; evidence suggests that lymph node metastasis is strongly correlated with the incidence of recurrence, the researchers noted. Therefore, there is a high interest in researching potential predictors of lymph node recurrence, they added.

TPO expression is known to be low in thyroid cancer. The authors hypothesized that TPO could serve as a predicting factor for lymph node metastasis in PTC.

Researchers collected clinical information from patients with PTC from The Cancer Genome Atlas (TCGA) and used it to compare TPO expression in healthy and cancerous tissue and also analyzed the relationship between lymph node metastasis and TPO expression. Additionally, the authors recruited 230 patients from the First Affiliated Hospital of Kunming Medical University, Montreal, Canada, and assessed TPO expression and correlation with lymph node metastasis using immunohistochemical analysis.

Results revealed TPO expression to be downregulated at an mRNA and protein level in patients with PTC. Furthermore, TPO expression was lower in patients with stages T3 and T4 than in patients with cancer stage T1. Lymph node metastasis also appeared more frequently in patients with lower TPO expression.

Statistical analysis showed that recurrence was significantly associated with lymph node metastasis and TPO expression.

“We have investigated that TPO expression may be associated with lymph node metastasis and recurrence in PTC patients through bioinformatics analysis as well as clinical and pathological findings in PTC patients in our center,” the authors concluded.


Li X, Cheng R. TPO as an indicator of lymph node metastasis and recurrence in papillary thyroid carcinoma. Sci Rep. Published online July 5, 2023. doi:10.1038/s41598-023-37932-1